Need help. I am unable to get past this error while configuring and starting App

Main error is - FATAL: The primary datasource cannot be reached. Access to the primary datasource is required. The Appian application will fail to deploy. Details: Unable to build EntityManagerFactory (APNX-1-4179-002)

I have verified both the primary and business datasources by logging into the oracle database and both of them exist.

Can you double check your connection settings in appian-ds.xml

Yes have verified that, see no issues there. Config for the primary is as below
<xa-datasource
jndi-name="jdbc/AppianPrimaryDS"
pool-name="OracleDS"
enabled="true"
use-java-context="false">
<xa-datasource-property name="serverName">localhost</xa-datasource-property>
<xa-datasource-property name="portNumber">1521</xa-datasource-property>
<xa-datasource-property name="databaseName">PADDYDB</xa-datasource-property>
<xa-datasource-property name="useUnicode">true</xa-datasource-property>
<xa-datasource-property name="characterEncoding">UTF-8</xa-datasource-property>
<xa-datasource-class>oracle.jdbc.xa.client.OracleXADataSource</xa-datasource-class>
<driver>oracle.jdbc</driver>
<security>
<security-domain>ds-name-security-primary</security-domain>
</security>
<transaction-isolation>TRANSACTION_READ_COMMITTED</transaction-isolation>
<xa-pool>
<min-pool-size>5</min-pool-size>
<max-pool-size>100</max-pool-size>
</xa-pool>
<timeout>
<blocking-timeout-millis>5000</blocking-timeout-millis>
<idle-timeout-minutes>5</idle-timeout-minutes>
</timeout>
</xa-datasource>

You are not specifying a "URL" property, refer to the docs here for an example of appian-ds.xml for Oracle RDBMS
forum.appian.com/.../Configuring_Relational_Databases

@tim, I had tried that too. No change. The file is generated by the Appian Config Manager, so I guess it should suffice. Tried all checks; unable to figure out the root cause. The error mentions the URL too - Caused by: java.sql.SQLException: Invalid Oracle URL specified: OracleDataSource.makeURL

Yes I saw that in the log hence the push towards your config. I understand that Appian Config Manager provides a file but it's configured for MySQL/SQL Server not Oracle by the looks of it. Try using the one from the docs linked above

Remove these two lines:

<xa-datasource-property name="useUnicode">true</xa-datasource-property>
<xa-datasource-property name="characterEncoding">UTF-8</xa-datasource-

they are for MySQL not for Oracle and are making your connection string invalid.

That's why your Caused by clauses state the following:

Caused by: java.lang.NoSuchMethodException: Method setUseUnicode not found

Thanks guys, this got resolved after I edited the Appian Configuration manager generated appian-ds.xml and put in the configuration mentioned for oracle in the wiki documentation. There should be some pointer about this in the Appian Config manager; didn't find any.